Transcutaneous access device

ABSTRACT

A transcutaneous access device comprises a sleeve having a flexible extensible main body with opposite ends defining collars. A catheter is loosely received in the main body and extends through the collar. Connectors permanently connect each collar to the catheter and an annular flexible skirt snugly surrounds the main body. The skirt is adjustable along the sleeve and/or the sleeve is bifurcated to accommodate two catheters for optimum fluid flow.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a division of Ser. No. 09/949,122, filed Sep.7, 2001, now U.S. Pat. No. _______, which is a continuation-in-part ofSer. No. 09/430,815, filed Oct. 29, 1999, now U.S. Pat. No. 6,355,020,which is a continuation-in-part of Ser. No. 09/738,011, filed Oct. 25,1996, now U.S. Pat. No. 5,882,341, which is a continuation-in-part ofSer. No. 09/499,543, now U.S. Pat. No. 5,662,616.

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION

[0002] This invention relates to a transcutaneous access device. Itrelates more particularly to a device of this type to facilitate accessto the body through the skin by catheters and similar percutaneousdevices.

BACKGROUND INFORMATION

[0003] There has of late been increasing use of catheters to provideprolonged or repeated access to the internal organs of chronically illpatients. For example, catheters are used to access a patient's venoussystem for the administration of intravenous (IV) fluids, antibiotics,and chemotherapy. Catheters are also implanted in patients who requirerepeated access to the peritoneum for peritoneal dialysis.

[0004] Other than occlusion, the most common complications arising withlongstanding implants are exit-site infection, tunnel infection, localabscesses and even sepsis. Many of these complications arise because theskin adjacent to the catheter does not heal to form a tight barrier toinfection. Rather, epidermal cells tend to invaginate or migrate inwardalong the catheter and never form a tight biological seal around thecatheter. Also, tunnels are created through which body fluids may exudethereby creating a site for infection.

[0005] In an attempt to overcome these problems, a catheter has beendevised which includes a button-like skirt with a raised neck and acentral hole for accommodating a tube. The tube has a corrugated segmentextending above the button neck which allows the external portion of thetube to be flexed so as to absorb shocks. The skirt, including a portionof the neck thereof, is covered with a porous material, such aspolyester velour, to allow for cell infiltration. When that device isimplanted, the epidermal cells tend to migrate or invaginate downwardalong the neck to the skirt where they form a biological seal with thecollagen and subcutaneous tissue growth on the porous covering of thebutton; see U.S. Pat. No. 4,886,502.

[0006] While that concept was relatively successful in animals, it hashad limited success in human trials because normal body motions causedstretching of the tissue adjacent to the catheter and exerted torsion onthe catheter. Such movements of the tissue relative to the button, whichis held stationary by the external segment of the catheter tube, resultsin disruption of the biological seal between the catheter and theadjacent tissue. Such disruption may also occur when the externalsegment of the catheter tube is moved accidentally or intentionally whenconnecting and disconnecting the catheter tube to the infusate source.

SUMMARY OF THE INVENTION

[0007] Accordingly, the present invention aims to provide atranscutaneous access device for a catheter which should circumvent mostof the problems caused by relative movement of the catheter and thetissue surrounding the catheter.

[0008] Another object of the invention is to provide a transcutaneousaccess device which, when implanted, provides a tight biological sealbetween the device and adjacent tissue.

[0009] A further object of the invention is to provide a device of thistype which reduces the risk of infection.

[0010] A further object is to provide such a device which allows a highfluid flow rate through the device.

[0011] Yet another object of the invention is to provide atranscutaneous access device which is relatively easy to manufacture inquantity.

[0012] Other objects will, in part, be obvious and will, in part, appearhereinafter. The invention accordingly comprises the features ofconstruction, combination of elements and arrangement of parts whichwill be exemplified in the following detailed description, and the scopeof the invention will be indicated in the claims.

[0013] The transcutaneous access device of this invention comprises aflat button with an opening therethrough and an integral upstandingtubular neck in registration with that opening. Formed as an integralextension of that neck is a flexible, extensible sleeve e.g. elastictubing or a bellows, whose free end is terminated by a collar whichconnects to a conventional access catheter whose catheter tube extendsall the way through the lumen formed by the sleeve or tube, neck andbutton of the access device.

[0014] In accordance with the invention, the lumen of the present deviceis large enough to provide appreciable clearance between the walls ofthe lumen and the access catheter so as to minimize contact between theaccess device and the access catheter. Thus, when the device isimplanted, the collar and upper end segment of the catheter tube arefree to move relative to the button and surrounding tissue.

[0015] In one preferred embodiment of the invention, the access deviceis permanently connected, via the free end of the sleeve, to thecatheter. In another embodiment, two similar access devices arepositioned back to back on the catheter with the free ends of theirsleeves connected to the catheter, preferably such that the sleeves arein a collapsed condition. Another embodiment provides a high fluid flowrate through the device.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] For a fuller understanding of the nature and objects of theinvention, reference should be had to the following detailed descriptiontaken in connection with the accompanying drawings, in which:

[0017]FIG. 1 is an isometric view with parts broken away of atranscutaneous access device incorporating the invention;

[0018]FIG. 2 is a sectional view with parts in elevation showing theFIG. 1 access device implanted in the body and ready for use;

[0019]FIG. 3 is a view similar to FIG. 1 of another embodiment of theaccess device;

[0020]FIG. 4 is a sectional view with parts in elevation showing yetanother embodiment of the invention;

[0021]FIG. 5 is a view in elevation of a further invention embodiment;

[0022]FIG. 6 is a similar view of still another device embodiment, and

[0023]FIG. 7 is a similar view of a high flow rate access deviceincorporating the invention.

DETAILED DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT

[0024] Referring to FIGS. 1 and 2 of the drawing, one embodiment of myaccess device comprises a flat, button-like main body or skirt 10 havinga central opening 12 and an array of three to six through-holes 14distributed around opening 12. Extending out from one side of skirt 10in registration with opening 12 is an integral, tubular neck 16 whoselumen is in registration with opening 12. Skirt 10 and neck 16 should bestiff enough to maintain their shapes but be somewhat flexible andcompliant so that when implanted they flex and “give” with the patient'sdermis. In the illustrated device, the neck 16 extends out from skirt 10at an angle; however, the neck could just as well be perpendicular tothe skirt 10.

[0025] The device also includes a highly flexible, extensible tubularsleeve 22 extending from the free end of neck 16. In the FIGS. 1 and 2device, sleeve 22 is a pleated accordion-like tube which forms a bellowsand which is terminated at its free end by a cylindrical collar 24.Thus, the sleeve 22 allows the collar 24 to be moved toward and awayfrom neck 16 in the order of 2-5 cm, as well as in all directions aboutthe longitudinal axis of neck 16. The skirt 10, neck 16, sleeve 22 andcollar 24 define a continuous, uniformly sized lumen 25 which extendsthrough the entire device.

[0026] As best seen in FIG. 2, the collar 24 is formed with an internallip 24 a to provide a mechanical connection to an associated accesscatheter as will be described later.

[0027] The access device, including the skirt 10, neck 16, sleeve 22 andcollar 24 are preferably formed of a flexible, thermally stable,biocompatible material such as flexible, medical grade polyurethane. Theaccordion-like sleeve 22 may be configured by placing a tubularextension of the neck 16 in a heated female mold and applying gaspressure inside the tube to force the tube walls to conform to the mold.The neck may then be secured to the button-like skirt 10 by welding.Alternatively, the device may be molded as a unitary part.

[0028] Preferably, the entire surface of the body or skirt 10 is coveredby a porous covering or bed 26 of a material such as medical gradepolyester (Dacron) velour. Such a covered skirt 10 is available as PartNo. 600K61121, from the U.S Catheter and Instrument Company ofGlenfalls, N.Y. The covering encourages cell infiltration and theformation of subcutaneous tissue and collagen and thus obtains a betterbond than the PTFE material used in the above patent.

[0029] Typically, when the access device is used for peritonealdialysis, the skirt 10 is in the order of 2.5 cm in diameter, the neck16 is about 0.5 cm long, the sleeve 22 is about 2 to 24 cm long and thediameter of the device's lumen 25 is in the order of 0.4 to 0.8 cm. Onthe other hand, when the device is used for vascular access, skirt 10may be smaller, e.g., 1 cm in diameter, with the lengths of the neck andsleeve being 0.5 cm and 4 cm, respectively. In that event, the lumen 25diameter may be in the order of 0.3 to 0.5 cm.

[0030] Referring to FIG. 2, the access device is implanted so that theskirt 10 is anchored in the subcutaneous tissue 32 and the covered neck16 extends out through the dermal layer 34 and epidermal layer 36 of theskin S through an opening O. In time, tissue growth penetrates thethrough-holes 14 to help anchor the access device. Those same holes alsoallow for fluid drainage and for tissue ingrowth. As noted previously,the covering 26 provides a porous bed to encourage the growth of tissueand collagen around the body 10 to provide a biological seal with theepidermal cells which migrate or invaginate down around neck 16 untilthey reach the covering 26.

[0031] The access device also includes an access catheter or cathetertube such as the one shown generally at 42 in FIG. 2. The illustratedcatheter is a vascular access catheter. However, the catheter could justas well be a peritoneal access catheter. Suffice it to say that thecatheter 42 includes a tube 44 which has an internal segment 44 a whichextends from the skin line along neck 16 and through body 10 to aselected infusion site such as the subclavian vein. The catheter tubealso includes an external segment 44 b which extends from the skin linethrough sleeve 22 and collar 24 to a Y-fitting 46 to which is connecteda pair of fluid inlet tubes 48 a and 48 b so as to allow fluid from twodifferent sources to be flowed to the catheter tube 44.

[0032] When the catheter 42 is properly seated in the access device, thelip 24 a of the device's collar 24 is arranged to releasably engage overa radial flange 46 a usually present at the lower end of the catheterfitting 46 to mechanically connect the catheter to the access device atthe free end of the device's flexible sleeve 22. However, as notedpreviously, the device's lumen 25 is sized to minimize contact with thecatheter tube 44 and so as not to inhibit motion of the catheter tube.Therefore, any motion of the internal catheter tube segment 44 a causedby movements of the patient's body is substantially decoupled from theimplanted portions of the access device, i.e., skirt 10 and neck 16. Bythe same token, if the external segment 44 b of the catheter tube 44should be moved accidentally or intentionally when connecting ordisconnecting the catheter, the accordion-like sleeve 22 is able toflex, extend and contract as needed to accommodate such movement so thatessentially no motion is coupled to the implanted portions of the accessdevice. Resultantly, a tight biological seal is maintained between theaccess device and the surrounding tissue.

[0033] Indeed, actual experiments with prototype devices have shown thatthere are no signs of infection at the implantation sites even after thedevices have been in place for prolonged periods.

[0034] Refer now to FIG. 3 which shows a second embodiment of mytranscutaneous access device. It is similar to the FIG. 1 embodiment,except that its button-like skirt 50, tubular neck 52 and extensiblesleeve 54 are formed as a unitary part. An annular connector member 56which may be similar to member 24 is provided at the free end of thesleeve 54. Thus, the device has an axial passage or lumen 58 whichextends the entire length of the device for accommodating a cathetertube 44 shown in phantom in FIG. 3. A suitable material for thebutton-neck-sleeve unit is medical grade polyurethane sold under thedesignation Tecoflex EG 80A by Thermedics, Inc., Woburn, Mass.

[0035] In this case, the extensible sleeve 52 is not accordion-like.Rather, it is a thin-walled (e.g., 0.030 in.), elastic tube which canreadily flex and extend lengthwise by the required amount, i.e., a fewcentimeters.

[0036] For most applications, sleeve 52 is more flexible and extensiblethan skirt 50 and neck 52. To achieve this result, the device is formedso that the skirt and neck have a greater wall thickness than thesleeve.

[0037] As in the FIG. 1 device, porous bed material is applied toexterior surfaces of the skirt 50 and neck 52. This material may be thesame as or similar to the material used for bed 26 described above.Here, however, the material is applied in two parts. An annular piece 60a of bed material is slid onto the sleeve 54 and neck 52 and folded asshown in FIG. 3 so that it covers the upper surface of the skirt andencircles the neck 52. It may be secured there by any suitable adhesive.To assure placement of the material piece 60 a at the correct elevationon the neck 52 indicium 62 may be molded into or inscribed around neck52.

[0038] Another annular piece 60 b of bed material is adhered to theundersurface of skirt 50, the opening through piece 60 b beingsubstantially the same size as lumen 58.

[0039] After being secured to skirt 50, the bed material pieces 60 a and60 b may be trimmed so that their outer edges are even with theperiphery of skirt 50.

[0040] The FIG. 3 embodiment of the device has all of the attributes ofthe FIG. 1 embodiment and functions in the same way described above inconnection with the FIG. 1 embodiment.

[0041] In many applications it is desirable to minimize the length ofthe annular space between the access device and the catheter tubeextending through that device. FIG. 4 illustrates an access device 70which accomplishes this objective. The device includes a catheter tube72 having a standard connector 74, e.g., a Luer, at its outer end.

[0042] This access device 70 includes an annular flexible skirt 78having a central opening 82 and an upstanding neck 78 a both of whichare appreciably larger than the outer diameter of tube 72. Neck 78 a ispermanently bonded to a flange 86 a formed at the lower end of aflexible, extensible sleeve or extension 86, e.g., a bellows (FIG. 4) orelastic tube (FIG. 3), having a collar 86 b at its opposite or upperend. As with the other device embodiments, means are provided forconnecting the collar 86 b to the catheter tube. In this case, however,the connecting means are constituted by a bonding 87 of collar 86 b tothe tube. If desired, an adapter sleeve 88 may be present between tube72 and collar 86 b to improve the bond. The sleeve 86, including itsflange 86 a and collar 86 b, has an inside diameter that is appreciablylarger than that of tube 72 so that the neck 78 a, skirt opening 82,sleeve 86, flange 86 a and collar 86 b define a continuous lumen whichextends through the entire device 70. This allows the collar 86 b to bemoved toward and away from skirt 78 as well as in all directions aboutthe longitudinal axis of the skirt.

[0043] As with the other access device embodiments, preferably skirt 78is made of or covered by a porous material, e.g. polyester, velour,which encourages cell ingrowth. Also, holes may be provided in theskirt.

[0044] As is apparent from FIG. 4, only a single tube extends fromcollar 86 b to connector 74. Therefore, there is no annular space aroundthat segment of the tubing which could be a site for unwanted bacterialgrowth.

[0045] Refer now to FIG. 5 which illustrates yet another embodiment ofmy invention consisting essentially of two of the access devicesdepicted in FIG. 4 positioned back to back on catheter tube 72. The twomirror-image access devices are shown generally at 70 and 70′ and theircorresponding parts carry the same identifying numerals (primed andunprimed) as in FIG. 4. The skirts 78 and 78′ of the two access devicesare connected together by adhesive bond 92 or the like and the collars86 b, and 86 b′ of the two devices are bonded or otherwise secured totubing 72. Thus, the two skirts 78, 78′ are free to float relative tothe catheter tube 72 and the collars.

[0046] Preferably, the collars 86 b, 86 b′ are connected to tube 72 suchthat the two sleeves 86, 86′ are under some compression, e.g., thebellows (FIG. 4) are collapsed to some extent. This assures that whenthe access device is implanted so that the skirts 78, 78′ are anchoredin subcutaneous tissue, any tension on the internal catheter tubesegment 72 a caused by movements of the patient's body is substantiallydecoupled from the implanted portions of the device, i.e., the skirts78, 78′ and necks 78 a, 78 a′. Likewise, if the external segment 72 b ofthe catheter tube 72 should be moved accidentally or intentionally whenconnecting or disconnecting the catheter, the external sleeve 86 is ableto flex, extend and contract as needed to accommodate such movement.Resultantly, no motion is coupled to the implanted portions of theaccess device which could upset the biological seal maintained betweenskirts 78, 78′ and the surrounding tissue.

[0047] Of course, in the FIG. 5 device, the two skirt layers 78, 78′could be combined into a single skirt with necks projecting fromopposite faces of that skirt.

[0048] In the back-to-back type access device depicted in FIG. 5, a parof bellows or elastic tubes 70, 70′ are permanently bonded to theinternal and external tube segment 72 a and 72 b, respectively. In someapplications, it may be desirable to employ a single bellows or elastictube. FIG. 6 shows generally at 100 an access device of this type. Itcomprises a single flexible, extensible sleeve 102 in the form of abellows or elastic tube which loosely receives a single length of tubing72 as in the FIG. 5 device. The opposite ends of the sleeve definecollars 103 which are permanently bonded to tube 72 preferably such thatsleeve 102 is under some compression. The access device 100 has a skirt104 and neck 104 a with a central opening 104 b which snugly receivesthe sleeve. A bonding 106 permanently secures the skirt 104 to sleeve102 midway along the sleeve.

[0049] Thus when the access device 100 is implanted, the distal end ofthe tube segment 72 a may be positioned at the infusion site and theskirt 104 positioned so that the skirt can be placed in the tissue underthe patient's skin line S, the skirt moving relative to tube 72subcutaneously as necessary.

[0050] Refer now to FIG. 7 which shows generally at 110 anotherembodiment of my access device which allows for a relatively high rateof fluid flow through the device. More particularly, in some cases itmay be desirable to effect cathetertization using a catheter with dualside-to-side lumens. For example, for central venous access, it isdesirable to go to the right internal jugular vein because it offers adirect route to the vena cava and atrium junction. For patientcompliance, the vein puncture is sought immediately above or behind theclavicle and the catheter(s) have an anterior exit in parallel with thesternum. When dual catheters are employed to maximize fluid flow, thecatheters usually exit the patient at different places at the patient'sskin line S. This means that there are two different sites for infectionto occur. FIG. 7 depicts an embodiment of my transcutaneous accessdevice which can accommodate two different catheters for increased fluidflow, yet which has all of the advantages described above for the otherdevice embodiments, particularly the one shown in FIG. 6.

[0051] The access device 110 comprises a pair of catheter tubes 112 and114 which may be identical. The upper or outer end of tube 112 isprovided with a connector 116. A similar connector 118 is provided atthe upper end of catheter tube 114. Both of these tubes may be the sameas or similar to the catheter tube 72 described above.

[0052] Surrounding comparable lengthwise segments of tubes 112 and 114is a flexible resilient sleeve 122, e.g. a bellows or elastic tube,which is bifurcated at its upper and lower ends. In other words, thesleeve 122 has a main axial segment or body 122 a whose diameter islarge enough to loosely surround both catheter tubes 112 and 114. At theupper end of the main segment 122 a, sleeve 122 divides to form twosmaller diameter branches 122 b and 122 c, the former branchaccommodating or receiving tube 112 and the latter branch receiving tube114. Similar branches 122 d and 122 e extend from the lower end of mainsegment 122 a to separately accommodate tubes 112 and 114. Thus, tube112 may extend through branch 122 b, main segment 122 a and branch 122d, while tube 114 may extend through branch 122 c, main segment 122 aand branch 122 e. The free ends of all of the branches define collars123 which are permanently secured to the corresponding tubes 112, 114 bybondings 124 or other suitable means.

[0053] Surrounding the main segment 122 a of sleeve 122 is an annularflexible skirt 126 which may be of a similar construction as the skirtsof the other device embodiments described above. Skirt 126 may bepermanently secured at a fixed location along the main segment 122 a. bya bond 128.

[0054] Preferably also, the collars 123 are connected to the respectivetubes 112 and 114 such that the sleeve 122 is under some compression,e.g. the bellows are collapsed to some extent. Resultantly, when theaccess device is implanted so that its skirt 126 is anchored insub-cutaneous tissue, tension on the implanted catheter tube segmentscaused by movements of the patient's body are substantially decoupledfrom the fixed portion of the device, i.e. skirt 126.

[0055] The access device depicted in FIG. 7 has a sleeve 122 in the formof a bellows whose branches are also flexible and extensible, i.e.smaller bellows. For those applications wherein the sleeve 122 only hasto provide a relatively small amount of flexibility and/or extension, itmay suffice that only the main segment 122 a be extensible. In otherwords, in that event, the branches 122 b to 122 e may be smallerdiameter sleeves whose free ends form the collars 123 secured to thecorresponding catheter tubes 112 and 114. Thus, the forming of theentire sleeve 122 as a bellows maximizes the amount of relative movementthat can occur between the ends of tubes 112, 114 and the skirt 126.

[0056] As seen from the foregoing, my transcutaneous access device is,for the most part, composed of plastic parts which can be made inquantity relatively easily and inexpensively. Therefore, it should findwide application wherever it is necessary to maintain catheters in situfor a long period of time.

[0057] It will thus be seen that the objects set forth above, amongthose made apparent from the preceding description, are efficientlyattained and, since certain changes may be made in the aboveconstruction without departing from the scope of the invention, it isintended that all matter contained in the above description or shown inthe accompanying drawings shall be interpreted as illustrative and notin a limiting sense.

[0058] It is also to be understood that the following claims areintended to cover all of the generic and specific features of theinvention described herein.

What is claimed is:
 1. A transcutaneous access device comprising asleeve including a flexible extensible main body having opposite ends, afirst pair of sleeve branches extending from one end of the main bodyand a second pair of sleeve branches extending from the opposite end ofthe main body, each branch of the pairs of sleeve branches having a freeend defining a collar; a pair of catheters having corresponding firstends and being loosely received in said sleeve, said pair of cathetersextending through said main body and different branches of said firstand second pairs of branches; means for permanently connecting thecollar of each sleeve branch to the catheter extending through thatbranch; an annular flexible skirt having an inner edge snuglysurrounding said main body, and securing means for permanently securingsaid skirt to said main body between said opposite ends thereof.
 2. Thedevice defined in claim 1 wherein the main body is accordion-like. 3.The device defined in claim 2 wherein at least one pair of sleevebranches is accordion-like.
 4. The device defined in claim 3 wherein thebranches of both pairs of sleeve branches are accordion-like.
 5. Thedevice defined in claim 1 wherein the sleeve comprises a thin-wallelastic tube bifurcated at both ends to form the first and second pairsof sleeve branches.
 6. The device defined in claim 1 wherein the entireinner edge of said skirt is bonded to the sleeve.
 7. The device definedin claim 1 and further including a bed of porous material substantiallycovering said skirt.
 8. The device defined in claim 1 and furtherincluding first and second connectors connected to said first ends ofthe pair of catheters.
 9. The device defined in claim 1 wherein saidsleeve is under lengthwise compression.